Hippocampus/Memory

Question 1

explicit memory

Answer 1

“that”

• true/false
• involves modeling of external world
• storage of facts/episodes
• highly flexible; many components

Question 2

implicit memroy

Answer 2

“how”

• not propositional (procedural)
• change in skilled behavior
• not conscious- motor learning

Question 3

explicit memory is broken down into

Answer 3

episodic–memory of personal experience

semantic– words/concepts

Question 4

structures involved in formation of explicit memory

Answer 4

hippocampus proper
dentate gyrus
subiculum
entorhinal cortex

Question 5

R hippocampus

Answer 5

spatial information

Question 6

L hippocampus

Answer 6

objects

Question 7

4 phases of explicit memory

Answer 7

1) encoding– new info is attended to and linked to existing information
2) storage- mechanism/actual brain parts of memory retention
3) consolidation- temporary to permanent
4) retrieval- recall

Question 8

medial temporal lobe

Answer 8

foramtion of new memories, but stored elsewhere

Question 9

short term/working memory

Answer 9

PFC
two components
- verbal information
-visuospatial information

Question 10

efficacy can be changed by

Answer 10

modulating neurons in PFC

• ACH on muscarinic receptors–>change Ca2+ act on nonselective cation channels
• act D1 dopamine R: working memory best when in intermediate range

Question 11

long term potentiation involves

Answer 11

functional changes in
-# post syn R
- post syn R channel fx
- presyn NT release
structural changes in
- # post syn spines (new synapses vs elim)
- size os spine heads
- spine stability

Question 12

perfornat pathway

Answer 12

axons from entor cells–>granule cells ind entate gyrus–>pyramidal cells CA3 of hippocampus (mossy fiber pathway) GLUTAMATE–>pyramidal neurons of CA1 (schaffer collaterals)–>back to entorinal/subiculum

Question 13

neurophysiolo postulate

Answer 13

following a high level of presyn activation, the size of synaptic field potentials (epsp amplitudes) in CA1 post syn neurons are larger than they were before and response remains long after presyn activity decreases

Question 14

damage to place cells

Answer 14

cannot do water maze

Question 15

LTP characterized by

Answer 15

• induction (bchemical process that arise from high levels of activation)
• expression (long term structural and functional changes)

Question 16

to induce LTP

Answer 16

presyn high lvel activity
post syn must depol
act on AMPA and NMDA
influx Ca into cell

Question 17

at rest

Answer 17

low levels of glutamate bind AMPA R–>small depolarization

glutamate binds NMDA R–> no current because Mg2+ binds channel

Question 18

high levels presyn activity

Answer 18

more glutamate–>act AMPA R–>large depol (-40mv)–>Mg2+ repelled from NMDA R–>positive ion flow into cell–greater depolarization

Question 19

NMDA therefore acts as a

Answer 19

coincidence detector

pharm blockers or deletion (cre/lox) inhibit LTP

Question 20

Ca into cell

Answer 20

activates a set of kinases (PKA, PKC, CAMKII)
1) inserts new AMPA R from vesicles at spine head
2) phos AMPAR (stabilizes, greater ion flux increases sensitivity)
3) dynamic restructing of actin cytoskeletion (enlargement, new spines)
4) increasd release of glut from presyn cel
(NO synthase–phos by CAMKII–>makes NO–>locally diffuse to presyn terminal

Question 21

BDNF

Answer 21

places a role in postsyn ampa r insertion

Question 22

ltp does/does not req gene expression

Answer 22

DOES

CAMKII, PKA, PKC act downstream to change gene transcription

Question 23

epigenetics

Answer 23

kinase phos KREB–>interacts with CBP –>histone acetylation–>restructures chromatin

Question 24

fear

Answer 24

enhanced meth of BDNF gene–>inhibits BDNF expression–>impairs hippocamp role in contextual fear memory

Question 25

purpse of LTD

Answer 25

erase imporatance of previously held memories in stressful situations so can focus on whats at hand

Question 26

stress

Answer 26

hippocampal neurons-->express both classical and gCC R and membrane gCC R-->changes kinase signaling
increases glut (therefore increases AMPA R)
increase LTD, dec LTP
->paradoxical, but resest threshold of lTP when something new need to be learned?